#3 Other marketers posts. Find other marketers that are in the same field as you and like and comment on their posts.

#4 Niche groups, these can be the biggest help to you. This is where you can find your best prospects.

Why?

Because they have the same interests as you.

Your first connection with your prospects is the most important. So take your time when you're connecting with others. Help them first. Do not Pitch your prospects. This is a great way to get them to run away from you. You are not a solicitor.

Bonus:
Make sure you offer your prospect solutions to their problems this is the best way to get people to join you and not run from you. Help them with what they need NOT what you want.